Why would there be wires plugging in to the top of my rear differential housing?

 

I believe that is where your speed is read from.

 

That's were the electric motor to move the truck is... duh...


Speed sensor for your rear wheel ABS. The speed pick up for your speedo is in the transmission or transfer case depending on if you have a 2wd or 4wd truck.

Here is a good read on your ABS and how it works...

https://www.dieselbombers.com/1st-ge...iagnostic.html

 

Thanks for the info, I have the anti-work brake system on my 1st gen